package com.example;
import java.io.IOException;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.Mapper;
import org.apache.hadoop.mapreduce.Reducer;
import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;

public class App {

    public static class TokenizerMapper extends Mapper<LongWritable, Text, Text, IntWritable> {
        
        private final static IntWritable one = new IntWritable(1);
        private Text label = new Text();

        public void map(LongWritable key, Text value, Context context) throws IOException, InterruptedException {
            // Skip the header line
            if (key.get() == 0) {
                return;
            }

            String[] tokens = value.toString().split(","); // Assuming CSV format
            if (tokens.length > 0 && tokens.length >= 60) {
                String target = tokens[59]; // Assuming zero-based indexing, change to 58 for the 59th column
                label.set(target);
                context.write(label, one);
            }
        }
    }

   public static class IntSumReducer extends Reducer<Text, IntWritable, Text, IntWritable> {

        private IntWritable result = new IntWritable();

        public void reduce(Text key, Iterable<IntWritable> values, Context context) throws IOException, InterruptedException {
            int sum = 0;
            for (IntWritable val : values) {
                sum += val.get();
            }
            result.set(sum);
            context.write(key, result);
        }
    }

    public static void main(String[] args) throws Exception {
        Configuration conf = new Configuration();
        Job job = Job.getInstance(conf, "Loan Default Count");
        job.setJarByClass(App.class);
        job.setMapperClass(TokenizerMapper.class);
        job.setCombinerClass(IntSumReducer.class);
        job.setReducerClass(IntSumReducer.class);
        job.setOutputKeyClass(Text.class);
        job.setOutputValueClass(IntWritable.class);
        FileInputFormat.addInputPath(job, new Path(args[0]));
        FileOutputFormat.setOutputPath(job, new Path(args[1]));
        System.exit(job.waitForCompletion(true) ? 0 : 1);
    }
}
